[PATCH] D43271: [Sparc] Include __tls_get_addr in symbol table for TLS calls to it

Tue Feb 20 11:14:12 PST 2018

This can be tested with llvm-mc, no?

Cheers,
Rafael

James Clarke via Phabricator via llvm-commits
<llvm-commits at lists.llvm.org> writes:

> jrtc27 created this revision.
> jrtc27 added a reviewer: JDevlieghere.
> Herald added subscribers: llvm-commits, fedor.sergeev, jyknight.
>
> Global Dynamic and Local Dynamic call relocations only implicitly
> reference __tls_get_addr, but it still needs to be in the symbol table
> to be bound at link time otherwise it fails to link. For details, see
> https://sourceware.org/bugzilla/show_bug.cgi?id=22832.
>
>
> Repository:
>   rL LLVM
>
> https://reviews.llvm.org/D43271
>
> Files:
>   lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
>   test/CodeGen/SPARC/tls.ll
>
>
> Index: test/CodeGen/SPARC/tls.ll
> ===================================================================
> --- test/CodeGen/SPARC/tls.ll
> +++ test/CodeGen/SPARC/tls.ll
> @@ -3,10 +3,10 @@
>  ; RUN: llc <%s -march=sparc   -relocation-model=pic    | FileCheck %s --check-prefix=pic
>  ; RUN: llc <%s -march=sparcv9 -relocation-model=pic    | FileCheck %s --check-prefix=pic
>  
> -; RUN: llc <%s -march=sparc   -relocation-model=static -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=v8abs-obj
> -; RUN: llc <%s -march=sparcv9 -relocation-model=static -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=v9abs-obj
> -; RUN: llc <%s -march=sparc   -relocation-model=pic    -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=pic-obj
> -; RUN: llc <%s -march=sparcv9 -relocation-model=pic    -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=pic-obj
> +; RUN: llc <%s -march=sparc   -relocation-model=static -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=v8abs-obj
> +; RUN: llc <%s -march=sparcv9 -relocation-model=static -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=v9abs-obj
> +; RUN: llc <%s -march=sparc   -relocation-model=pic    -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=pic-obj
> +; RUN: llc <%s -march=sparcv9 -relocation-model=pic    -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=pic-obj
>  
>  @local_symbol = internal thread_local global i32 0
>  @extern_symbol = external thread_local global i32
> @@ -116,4 +116,15 @@
>  ; pic-obj:    0x{{[0-9,A-F]+}} R_SPARC_TLS_GD_ADD extern_symbol 0x0
>  ; pic-obj:    0x{{[0-9,A-F]+}} R_SPARC_TLS_GD_CALL extern_symbol 0x0
>  ; pic-obj: ]
> +; pic-obj:      Symbols [
> +; pic-obj:        Symbol {
> +; pic-obj:          Name: __tls_get_addr ({{[0-9]+}})
> +; pic-obj-NEXT:     Value: 0x0
> +; pic-obj-NEXT:     Size: 0
> +; pic-obj-NEXT:     Binding: Global (0x1)
> +; pic-obj-NEXT:     Type: None (0x0)
> +; pic-obj-NEXT:     Other: 0
> +; pic-obj-NEXT:     Section: Undefined (0x0)
> +; pic-obj-NEXT:   }
> +; pic-obj:      ]
>  
> Index: lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
> ===================================================================
> --- lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
> +++ lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
> @@ -193,14 +193,30 @@
>  void SparcMCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
>    switch(getKind()) {
>    default: return;
> +  case VK_Sparc_TLS_GD_CALL:
> +  case VK_Sparc_TLS_LDM_CALL: {
> +    // The corresponding relocations reference __tls_get_addr, as they call it,
> +    // but this is only implicit; there is no connection in the ELF file
> +    // between the relocation and the symbol, other than the specification for
> +    // the semantics of the relocations. However, the symbol must be included
> +    // in our symbol table despite the lack of references to it, since it needs
> +    // to be bound during linking for these relocations. For details see
> +    // https://sourceware.org/bugzilla/show_bug.cgi?id=22832.
> +    MCSymbol *Symbol = Asm.getContext().getOrCreateSymbol("__tls_get_addr");
> +    Asm.registerSymbol(*Symbol);
> +    auto ELFSymbol = cast<MCSymbolELF>(Symbol);
> +    if (!ELFSymbol->isBindingSet()) {
> +      ELFSymbol->setBinding(ELF::STB_GLOBAL);
> +      ELFSymbol->setExternal(true);
> +    }
> +    LLVM_FALLTHROUGH;
> +  }
>    case VK_Sparc_TLS_GD_HI22:
>    case VK_Sparc_TLS_GD_LO10:
>    case VK_Sparc_TLS_GD_ADD:
> -  case VK_Sparc_TLS_GD_CALL:
>    case VK_Sparc_TLS_LDM_HI22:
>    case VK_Sparc_TLS_LDM_LO10:
>    case VK_Sparc_TLS_LDM_ADD:
> -  case VK_Sparc_TLS_LDM_CALL:
>    case VK_Sparc_TLS_LDO_HIX22:
>    case VK_Sparc_TLS_LDO_LOX10:
>    case VK_Sparc_TLS_LDO_ADD:
>
>
> Index: test/CodeGen/SPARC/tls.ll
> ===================================================================
> --- test/CodeGen/SPARC/tls.ll
> +++ test/CodeGen/SPARC/tls.ll
> @@ -3,10 +3,10 @@
>  ; RUN: llc <%s -march=sparc   -relocation-model=pic    | FileCheck %s --check-prefix=pic
>  ; RUN: llc <%s -march=sparcv9 -relocation-model=pic    | FileCheck %s --check-prefix=pic
>  
> -; RUN: llc <%s -march=sparc   -relocation-model=static -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=v8abs-obj
> -; RUN: llc <%s -march=sparcv9 -relocation-model=static -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=v9abs-obj
> -; RUN: llc <%s -march=sparc   -relocation-model=pic    -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=pic-obj
> -; RUN: llc <%s -march=sparcv9 -relocation-model=pic    -filetype=obj | llvm-readobj -r | FileCheck %s --check-prefix=pic-obj
> +; RUN: llc <%s -march=sparc   -relocation-model=static -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=v8abs-obj
> +; RUN: llc <%s -march=sparcv9 -relocation-model=static -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=v9abs-obj
> +; RUN: llc <%s -march=sparc   -relocation-model=pic    -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=pic-obj
> +; RUN: llc <%s -march=sparcv9 -relocation-model=pic    -filetype=obj | llvm-readobj -r -t | FileCheck %s --check-prefix=pic-obj
>  
>  @local_symbol = internal thread_local global i32 0
>  @extern_symbol = external thread_local global i32
> @@ -116,4 +116,15 @@
>  ; pic-obj:    0x{{[0-9,A-F]+}} R_SPARC_TLS_GD_ADD extern_symbol 0x0
>  ; pic-obj:    0x{{[0-9,A-F]+}} R_SPARC_TLS_GD_CALL extern_symbol 0x0
>  ; pic-obj: ]
> +; pic-obj:      Symbols [
> +; pic-obj:        Symbol {
> +; pic-obj:          Name: __tls_get_addr ({{[0-9]+}})
> +; pic-obj-NEXT:     Value: 0x0
> +; pic-obj-NEXT:     Size: 0
> +; pic-obj-NEXT:     Binding: Global (0x1)
> +; pic-obj-NEXT:     Type: None (0x0)
> +; pic-obj-NEXT:     Other: 0
> +; pic-obj-NEXT:     Section: Undefined (0x0)
> +; pic-obj-NEXT:   }
> +; pic-obj:      ]
>  
> Index: lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
> ===================================================================
> --- lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
> +++ lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp
> @@ -193,14 +193,30 @@
>  void SparcMCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
>    switch(getKind()) {
>    default: return;
> +  case VK_Sparc_TLS_GD_CALL:
> +  case VK_Sparc_TLS_LDM_CALL: {
> +    // The corresponding relocations reference __tls_get_addr, as they call it,
> +    // but this is only implicit; there is no connection in the ELF file
> +    // between the relocation and the symbol, other than the specification for
> +    // the semantics of the relocations. However, the symbol must be included
> +    // in our symbol table despite the lack of references to it, since it needs
> +    // to be bound during linking for these relocations. For details see
> +    // https://sourceware.org/bugzilla/show_bug.cgi?id=22832.
> +    MCSymbol *Symbol = Asm.getContext().getOrCreateSymbol("__tls_get_addr");
> +    Asm.registerSymbol(*Symbol);
> +    auto ELFSymbol = cast<MCSymbolELF>(Symbol);
> +    if (!ELFSymbol->isBindingSet()) {
> +      ELFSymbol->setBinding(ELF::STB_GLOBAL);
> +      ELFSymbol->setExternal(true);
> +    }
> +    LLVM_FALLTHROUGH;
> +  }
>    case VK_Sparc_TLS_GD_HI22:
>    case VK_Sparc_TLS_GD_LO10:
>    case VK_Sparc_TLS_GD_ADD:
> -  case VK_Sparc_TLS_GD_CALL:
>    case VK_Sparc_TLS_LDM_HI22:
>    case VK_Sparc_TLS_LDM_LO10:
>    case VK_Sparc_TLS_LDM_ADD:
> -  case VK_Sparc_TLS_LDM_CALL:
>    case VK_Sparc_TLS_LDO_HIX22:
>    case VK_Sparc_TLS_LDO_LOX10:
>    case VK_Sparc_TLS_LDO_ADD:
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits